MINNEAPOLIS (Reuters) - Fire crews were called on Monday to the Minnesota governor's residence in St. Paul, Minnesota, after staff members opened a letter and found what turned out to be a small amount of non-threatening white powder, a state spokesman said.

The letter was received and opened in a building separate from the main residence for Democratic Governor Mark Dayton, said Doug Neville, a spokesman for the Minnesota Department of Public Safety.

"The content of the letter was non-threatening," he said.

When staff detected a small amount of white powder, they contacted the Minnesota State Patrol, which contacted the St. Paul Fire Department to respond to the residence, he said.

"The governor was in the main residence at the time, not in close proximity to the letter," Neville said. "The letter posed no threat to the governor."